Aptamer-Driven Toxin Gene Delivery in U87 Model Glioblastoma Cells

Abstract

A novel suicide gene therapy approach was tested in U87 MG glioblastoma multiforme cells. A 26nt G-rich double-stranded DNA aptamer (AS1411) was integrated into a vector at the 5′ of a mammalian codon-optimized saporin gene, under CMV promoter. With this plasmid termed “APTSAP”, the gene encoding ribosome-inactivating protein saporin is driven intracellularly by the glioma-specific aptamer that binds to cell surface-exposed nucleolin and efficiently kills target cells, more effectively as a polyethyleneimine (PEI)-polyplex. Cells that do not expose nucleolin at the cell surface such as 3T3 cells, used as a control, remain unaffected. Suicide gene-induced cell killing was not observed when the inactive saporin mutant SAPKQ DNA was used in the (PEI)-polyplex, indicating that saporin catalytic activity mediates the cytotoxic effect. Rather than apoptosis, cell death has features resembling autophagic or methuosis-like mechanisms. These main findings support the proof-of-concept of using PEI-polyplexed APTSAP for local delivery in rat glioblastoma models.

Using ELP Repeats as a Scaffold for De Novo Construction of Gadolinium-Binding Domains within Multifunctional Recombinant Proteins for Targeted Delivery of Gadolinium to Tumour Cells

“…To confirm the ability of the obtained MBS-proteins to interact with (or enter into) tumour cells, in vitro experiments were carried out using the IN Cell Analyzer (fluorescence microscopy). The U87MG cell line was chosen as a candidate due to expression surface nucleolin [ 67 , 68 ], which can serve as a receptor for F3 peptide [ 69 ]. Moreover, U87MG expresses abundant integrin αvβ3 ([5.2 ± 1.4] × 10 4 receptors/cell, or 18 ± 6 receptors/μm 2 ) [ 70 ], which can bind the RGD peptide.…”

Aptamer-conjugated gold nanoparticles and their diagnostic and therapeutic roles in cancer

“…A stable three-dimensional structure is the basis for an aptamer to perform the target recognition function ( Hermann and Patel, 2000 ), which makes it different from antibodies that depend on antigen-antibody binding. Adapters can recognize the targets of proteins ( Farrow et al, 2022 ), drugs( Tang et al, 2020 ), metal ions( Guo et al, 2021 ), toxins( di Leandro et al, 2021 ), cells( Kordasht and Hasanzadeh, 2020 ) and other types of substances. In addition, aptamers also have the advantages of easy modification or coupling of functional groups, strong tissue penetration, suitable thermal/chemical stability, and low immunogenicity.…”

“…An aptamer is an unnatural oligonucleotide consisting of 25–90 nucleotides (usually RNA or DNA), which can be folded into a complex three-dimensional structure through intramolecular interactions ( Ellington and Szostak, 1990 ). Adapters can selectively and exclusively identify various types of targets, such as proteins ( Chen et al, 2019 ), drugs ( Parker et al, 2019 ), heavy metal ions ( Guo et al, 2021 ), toxins ( di Leandro et al, 2021 ), and cells ( Kordasht and Hasanzadeh, 2020 ). For a long time, immunological and genomic methods have dominated the detection market for tumour markers ( Gao et al, 2019 ).…”

Bio-Tailored Sensing at the Nanoscale: Biochemical Aspects and Applications

“…Despite their natural occurrence, aptamers can be easily synthesized at low cost and are particularly targeted for different applications, including sensing. Indeed, though aptamers are well-known as very proficient therapeutic tools, for instance in cancer therapy [ 21 , 22 , 23 ], their application in biosensing has recently been propelled by many examples reporting on molecular, ion and cell detection in food and water as well as in diagnostics [ 24 ]. The combination of aptamers with nanomaterials is not an exception.…”